Epidemiologic Investigation on an Outbreak of Cholera in Gyeongsangbuk-do, Korea, 2001 / 예방의학회지

ABSTRACT

OBJECTIVES: This study was carried out to investigate the cause, magnitude and transmission route of the cholera outbreak in 2001. METHODS: The study population were those persons who ingested foods at the restaurant, were confirmed as cholera patients, had symptoms of diarrhea and served as workers at the restaurant. A questionnaire survey and microbiological examinations on the microbes isolated from rectal swabs were conducted. Of the cases, 316 food histories were surveyed by an analysis of the restaurant menu. RESUJLTS There were 139 confirmed cases of cholera reported in Korea in 2001. Of these, 104 were related to the restaurant. By region, Gyeongsangbuk-do had the highest incidence with 91 cases. Of these 91 cases, 74 had ingested foods at the restaurant, 2 were employees and 3 were secondary infection cases within the families. The results of the odds ratio analysis of the 316 persons having ingested foods at the restaurant were as follows sandwiches 5.07 (95% CI, 1.85-14.59), soybean curd 2.45 (95% CI, 1.09-5.56), noodles 2.34 (95% CI, 1.24-4.42), steamed squid 2.01 (95% CI, 1.17-3.47) and vinegared rice 1.82 (95% CI, 1.08-3.09). It was certain the restaurant in question was the cause of the 2001 outbreak. CONCLUSIONS: We suspected that more than one restaurant employee contaminated foods served at the restaurant. In addition, eating raw fishes purchased at the Pohang Fisheries infected the employees of the restaurant. There is a possibility that these raw fishes were themselves contaminated by cholera bacilli in the sea.